I was plagued by niggles and injuries for the first few weeks which sort of hindered my progress to begin with.

But none of those things came into play on Sunday.

Because bizarrely, Sunday was by far the most comfortable long run I’ve done. There was no runner’s wall, no knee pain, no stomach cramp.

The night before

I was told by everyone that what you do the day before is almost as important as what you do on the day of a marathon.

I felt so stiff on Saturday – my ankle was swollen, my knees were giving me jip. I was tired. And nervous. So I went for a swim and steam at the gym before going to a final Adidas Runners meeting where I had my name printed onto my charity shirt.

My PT started texting me on Saturday morning with a series of Whatsapp messages which simply read: ‘CARBS, CARBS, CARBS’.

(Picture: Miranda Larbi)

48 hours, you’re advised to carb up – which is good for me because I basically live off carbs and tomatoes. I continued to eat my weight in flapjacks and for lunch on Saturday had a bowl of pasta with tomato and caper sauce. For dinner, which I made sure I’d eaten by 8pm, I had some nut patty burgers.

The start

On the morning of a marathon, you’re supposed to do exactly what you’ve been doing before your practice runs. Try nothing new. Eat nothing out of the ordinary.

I got up at 5:45am and shoved down the same porridge and peanut butter combo I’ve been having every day, along with three cups of coffee to try to poo as much as possible before leaving the house (sorry, but it’s true). When I was on my way to the station, I took two Imodiums. I did not poo again for two days.

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Everyone says to get to the start line early in order to avoid waiting for the loos. I got to Maze Hill just before 9am (the start gun was at 10am) and stood in a queue until 9:45. While I was in that bog queue however, I talked to a group of older marathon runners who had each run at least three races. They told me that they’d all got into marathon running in their 40s and 50s – and each was going for another sub-4 hours time.

‘When you’re young, it’s all about speed,’ one said.

‘It’s when you get older that you can concentrate on long distance – you’ve got plenty of time to get your technique perfect!’

And that really calmed me down. This was my first marathon. After all, the hypnotherapist I saw a few weeks ago stressed the importance of acknowledging that I was a ‘trainee’ marathon runner – mistakes might be made but there’d be plenty of time for improvement.

At the start line, I chatted someone attempting to break a world record dressed as a tree, and found a kindred spirit in a charity worker who had also never wanted to run a marathon before but who had been railroaded into it by her work.

(Picture: Miranda Larbi)

We started off just behind the 4:45 hour pace setter who promptly disappeared for a piss after the first mile. We ran together until Greenwich, discussing her recent breakup, the fact that her face swelled up when she ran, our Desert Island Discs options. Eventually, she too went off for a pee around mile 5, and I put in my headphones.

Running through Greenwich was insane. The streets were lined with hundreds of people shouting our names, clapping, whooping. There were street bands. Every inch of the pavement was packed with well-wishers. Even if you wanted to stop at that early point, you couldn’t have because the momentum of the crowd and of the runners propelled you forward like a wave. I ran with the biggest smile on my face like a complete loon.

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And that pretty much continued for an hour. Running across Tower Bridge – the 20km point – was incredible. Looking over the sides across the Thames, and taking in such an iconic symbol of London was completely spine tingling. Here we all were, running for so many amazing causes in our incredible city. ‘Humbling’ doesn’t really cut it.

The middle

There’s a long stretch in Wapping called the Highway and when you’re going down it, you see all the elite runners going up it. In my mind, that meant that it wasn’t going to be that long – that there’d be a roundabout a mile or so down which we’d run around and come back up.

Logically of course, that doesn’t make sense because those elite runners were going to finish at least two hours ahead of us on the other side. But logic doesn’t play a huge role in running marathons.

Anyway, that stretch of road was awful. It took us through the most desolate, uninspiring landscapes that never seemed to end.

(Picture: Ella Byworth for Metro.co.uk)

The anticipation of the turnaround drove me nearly mad. WHEN WERE WE GOING TO TURN BACK FFS? At the very start of the road, I saw one of my best mates and her family who were there to support her insane husband (who finished in 2:50), screaming my name and I was keen to be yelled at again.

But the road seemed never ending. People started dropping like flies. I saw bodies at the sides of the road covered in foil. People starting to walk. Loads of guys stopped to lean against walls to try and stretch out cramped calves.

And it was at this point – around mile 18 – that I saw three fantastic posters that actually made me snort out loud.

‘Run like your ex is chasing you’ was the first, closely followed by ‘You’re running better than Teresa May’s government’. But the one that gave me an extra push and seriously – if you’re reading this then you’re an absolute star – was: ‘I don’t know you but I’m proud of you’.

Can you imagine someone taking the time to tell a stranger that? THIS IS THE CITY WE LIVE IN.

If you’re planning on running a marathon, then support really is everything. My parents tried to track me on the official app but apparently missed me at literally every mile station they tried to get to. I also had mates standing at various places and accidentally ignored them all shouting my name. But at mile 21, I saw my boyfriend and his pals and I’m not sure I’ve ever been more relieved to see a group of people in my entire life. I was ecstatic.

I should point out that I actually hugged the wrong person here and ended up basically ignoring my bf because he was standing in an inconvenient place (Picture: Miranda Larbi)

My charity also had their balloons and stand at mile 23 and they gave me an extra boost.

The anticipation of seeing people you know or getting support is really good for keeping going at the same speed. You know you’re going to get an extra push and you don’t want your mates to see you flagging. Because I didn’t quite know where anyone was, I pretty much ran the whole thing thinking that they might be waiting around the corner. And after mile 23, I was conscious that there was beer waiting so I didn’t really have a choice but to keep cantering on.

The finish

Whatever you might think, the last bit of a marathon is the worst bit. The last two miles were the longest two miles of my life.

I kept saying to myself that my usual jogging route was longer than what I had left to run but honestly, the embankment felt never ending. I’m pretty sure I saw some guy sh*t himself around that time too (at least, he was walking pigeon-legged, holding onto his arse).

After passing parliament, I thought about putting a bit of speed into the finish but I could feel that cramp was about to set in in my right calf so rather than going faster, I strode out slightly longer. 800m…400m…honestly it was like it was never going to end. But finally, I crossed the finish line in 4:24 hours.

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Once I stopped running, the real struggle started. I could barely speak. I could barely walk. I could barely see. In fact, I felt like I’d been on the lash for the past four hours. It was complete delirium.

I was eventually found by my mum and mates lying down at the meet and greet area. Your feet start to swell almost immediately once you stop moving so I changed into my OOFOS flip flops, and as soon as I’d got it together enough to put on my tracksuit, we hot footed it (read: was dragged) to the nearest pub for the first pint in four months.

You’ll see the same people popping up again and again and you’ll feel like you’ve bonded for life even if you haven’t actually spoken a word to each other

All along the course, there are loads of running clubs like Run Dem Crew and Adidas Runners cheering on their troops – you’ll start planning which you’re going to join after you’ve recovered from the current battle in hand